8.4 Late Spring - Leafcutter Bee Incubation

This pest is found while incubating your leafcutter bee cocoons.

Parasitic wasp: Pteromalus

What It Is: Also known as the Canadian chalcid, pteromalus wasps are gnat-sized (2-3mm) black parasitic wasps that are active while leafcutter bees are emerging.

What You See: You may find small exit holes along the sides of your leafcutter bee cocoons.

Effect on Bees: The sneaky pteromalus wasp lays her eggs within the freshly laid leafcutter bee egg. The pteromalus larvae will overwinter within the leafcutter bee cocoons and emerge before the leafcutter bees, laying their wasp eggs in the remaining incubating leafy cocoons.

What You Can Do: During leafcutter cocoon incubation, protect your leafcutter bee cocoons in our fine mesh BeeGuard Bag. Squish any pteromalus, which emerges about 9-12 days after you begin incubation. During leafcutter bee nesting, spray a fine mist of water to knock flying adult pteromalus wasps out of the air and then squish them.